Endogenous Stimuli-Sensitive Multistage Polymeric Micelleplex Anticancer Drug Delivery System for Efficient Tumor Penetration and Cellular Internalization

• Published in: Advanced healthcare materials 2015-10, Vol.4 (15), p.2206-2219
• Main Authors: Li, Junjie, Ke, Wendong, Li, Hui, Zha, Zengshi, Han, Yu, Ge, Zhishen
• Format: Article
• Language: English
• Subjects: Animals; anticancer drug delivery; Antineoplastic Agents - chemistry; Antineoplastic Agents - pharmacology; Cell Line, Tumor; Cellular; charge conversion; Dendrimers; Drug Delivery Systems; Drugs; Hydrogen-Ion Concentration; Male; Mice; Mice, Inbred ICR; micelleplex; Micelles; Multistage; Nanostructure; Nanostructures - chemistry; Neoplasms - drug therapy; Penetration; Polyesters - chemistry; Polyethylene Glycols - chemistry; Polyethylene Glycols - pharmacology; Polymers - chemistry; Polymers - pharmacology; responsive drug release; tumor penetration; Tumors
• ISSN: 2192-2640; 2192-2659
• DOI: 10.1002/adhm.201500379

To efficiently deliver anticancer drugs to the entire tumor tissue and cancer cells, an endogenous stimuli‐sensitive multistage polymeric micelleplex drug delivery system is developed via electrostatic complexation between poly(ethylene glycol)‐block‐poly[(N′‐dimethylmaleoyl‐2‐aminoethyl)aspartamide]‐block‐poly(ε‐caprolactone) (PEG‐b‐PAsp(EDA‐DM)‐b‐PCL) triblock copolymer micelles and cisplatin prodrug (Pt(IV))‐conjugated cationic poly(amidoamine) dendrimers (PAMAM‐Pt(IV)). The micelleplexes maintain structural stability at pH 7.4 ensuring long blood circulation and high tumor accumulation level, while they exhibit triggered release of secondary PAMAM‐Pt(IV) dendrimer nanocarriers at tumoral acidity (≈pH 6.8) due to acid‐labile charge‐reversal properties of PAsp(EDA‐DM) component under mildly acidic condition. The released PAMAM delivery nanocarriers with small size and slightly positive charges exhibit significantly deep tumor tissue penetration and efficient cellular internalization, followed by release of active cisplatin anticancer drug in intracellular reducing medium. In vivo investigation reveals that the Pt(IV)‐loading micelleplexes significantly suppress tumor growth via intravenous injection due to synergistic effect of long circulation in bloodstream, high tumor accumulation, deep tumor tissue penetration, and efficient cellular internalization. Thus, the micelleplexes with stimuli‐responsive multistage release feature show great potentials for better therapeutic efficacy of cancer especially through enhanced tumor penetration and cellular internalization. A responsive multistage polymeric micelleplex drug delivery system is developed for deep tumor penetration and high‐efficiency cellular internalization after long circulation and tumor accumulation via systemic administration. The micelleplex shows tumor acidity‐responsive release of PAMAM‐Pt(IV) nanocarrier with small size and slightly positive charges to facilitate tumor tissue penetration and cellular uptake, followed by intracellular reduction‐triggered active cisplatin release.